Sheet separator for copying machines

ABSTRACT

A sheet separator for separating an original sheet from a juxtaposed copy sheet as the sheets are advanced longitudinally through a copying machine, the sheet separator including means for establishing opposite areas of reduced air pressure, one such area adjacent each sheet, tending to pull the sheets from one another and a plurality of guides for deflecting the juxtaposed sheets from one such area toward the other area at spaced lateral locations such that the sheets are effectively separated.

United States Patent Inventors: Robert P. Neel), Wake Forest; Henry W.

Patrick, Raleigh, both of N.C.

Diazit Company Inc., Youngsville, N.C.

Feb. 3, 1971 Int. Cl r t t t ..B65h 29/64 Field of Search ..27 H64, 74, 18,28

References Cited UNITED STATES PATENTS 7/1944 Trump ..27 1/74 X Neeb et al. 1 July 4, 1972 54 SHEET SEPARATOR FOR COPYING 2,822,170 2/1958 Frantz ..27l/64 MACHINES 3,408,065 10/1968 Goodman et all. ..27l/64 Primary Examiner loseph Wegbreit Assistant ExaminerBruce H. Stoner, Jr. AttorneySamuelson & Jacob 57 ABSTRACT 10 Claims, 3 Drawing Figures PATENTEBJUL 41912 3,674,257

sum 10F 2 mvENToR, Roeawr P Neaes HENRY W. PATRICK HTTOR mes P'A'TENTEDJUL 4 m2 SHEET 20F 2 INVENTORS ROBERT P N55 HENRY W. PATR\CK QTTONEYS SHEET SEPARATOR FOR COPYING MACHINES The present invention relates generally to copying machines and pertains, more specifically, to sheet separators for separating juxtaposed original and copy sheets as the juxtaposed sheets are advanced through a copying machine.

A wide variety of copying machines are presently available for making duplicate copies of original documents such as letters, charts, drawings, and the like. Among the various types of copying machines available today, the diazo-type copying machine has had a long history, marked by wide commercial acceptance. More recent developments in diazo copying machines have rendered such machines much more compact than those of the past, making it advantageous to employ a greater number of such machines in more locations, and for more diverse uses.

In a diazo-type copying machine, as well as in certain other copying machines, the document to be copied, or the original sheet, is juxtaposed with a copy sheet and the juxtaposed sheets are advanced through the machine to first expose the juxtaposed sheets to light and thus form a latent image of the original material upon the copy sheet. The sheets are then separated and the copy sheet is further processed to develop the latent image into a fully visible image.

Because the juxtaposed original and copy sheets are placed in intimate contact for the exposure portion of the above sequence, separation of the sheets can pose a problem, particularly in diazo copying machines, where the original sheet is in the form of a light-weight transparency and tends to cling to the heavier weight copy sheet. The problem of separation is compounded further in modern compact diazo copying machines where very little space is available for separation devices and very little time is available within which separation must be accomplished prior to advancing the copy sheet for further processing. It would be advantageous, then, to have available a compact sheet separator which can accomplish the separation of juxtaposed original and copy sheets quickly and effectively as the sheets are advanced through a copying machine.

It is therefore an important object of the invention to provide a compact sheet separator which effectively will separate an original sheet from a juxtaposed copy sheet as the juxtaposed sheets are advanced through a copying machine.

Another object of the invention is to provide a sheet separator which requires relatively little space and which will act upon juxtaposed original and copy sheets to effect relatively quick and positive separation of the copy sheet from the original sheet.

Still another object of the invention is to provide a sheet separator which is simple in construction and is compatible with current compact diazo copying machines.

A further object of the invention is to provide a sheet separator which is simple in construction and dependable in operation and which is efficient in that it consumes relatively small amounts of power. i

The above objects, as well as still further objects and advantages, are attained by the invention which may be described briefly as providing, in a copying machine wherein an original sheet is initially juxtaposed with a copy sheet, the juxtaposed sheets are advanced longitudinally in the machine along a first path of travel, and the original and copy sheets are subsequently separated from one another such that one of the sheets follows a second path of travel which diverges from the first path of travel, a sheet separator comprising first means for establishing a first area of reduced air pressure along the first path of travel, the first area extending longitudinally for a relatively short distance along the first path of travel and extending laterally over approximately the width of the advancing sheets, second means for establishing a second area of reduced air pressure along the second path of travel, the second area essentially overlapping at least a portion of the first area and diverging therefrom in the direction of advancement of the sheets, and a plurality of guides intercepting the first path of travel along a portion of the longitudinal extent of the first area and spaced laterally over the lateral extent of the first area, the guides being raised from the first area toward the second area to raise the advancing juxtaposed sheets from the first area toward the second area at laterally spaced locations to effect separation of the juxtaposed sheets such that one sheet follows one of the diverging paths of travel while the other sheet follows the other of the paths of travel as the sheets pass between the areas.

The invention will be more fully understood, while still further objects and advantages will be made apparent, in the following detailed description of an embodiment of the invention illustrated in the accompanying drawing, in which:

FIG. 1 is an elevational, partially diagrammatic, cross-sectional view of a diazo-type copying machine employing a sheet separator constructed in accordance with the invention;

FIG. 2 is an enlarged fragmentary cross-sectional view of the sheet separator of FIG. 1; and

FIG. 3 is a fragmentary perspective view of a portion of the sheet separator.

Referring now to the drawing, and expecially to FIG. 1 thereof, a diazo copying machine is illustrated, at least partially in diagrammatic fashion, at 10 and is shown to be of a compact variety having a base 12 with depending feet 14 enabling the machine 10 to be placed upon a table top 16 or a like stand. The housing 18 of copying machine 10 is open at the front 19 to enable an operator of the machine 10 to place a sheet 22 of copy paper with a transparent original sheet 20 juxtaposed with the copy sheet 22 upon an entrance platform 24 within the housing 18 and then manually advance the juxtaposed original sheet 20 and copy sheet 22 through an entrance slot 26 and into the printer section 28 of the machine.

The aligned leading edges 30 and .32 of the original and copy sheets 20 and 22, respectively, will then be gripped between a plurality of printer belts 34 and a transparent printer cylinder 36 which is rotated in a counterclockwise direction by movement of the belts 34 in the direction indicated in FIG. 1. The belts 34 are driven by a drive roller 38 and pass around a plurality of idler rollers 40. A plurality of tubular fluorescent lamps 42 are mounted within the printer cylinder 36 and serve as a source of light which will pass through the transparent wall of the cylinder 36 and through the transparent original sheet 20 as the juxtaposed sheets 20 and 22 are carried along between the cylinder 36 and the belts 34 to establish a latent image of the original material upon the copy sheet. The juxtaposed original and copy sheets 20 and 22 will emerge from between the printer belts 34 and the printer cylinder 36 at 44 where the leading edges 30 and 32 of the juxtaposed sheets will engage a pick-off strip 46 and follow a path of travel across a relatively short platform 48 to pass into the entrance chute 49 of a sheet separator illustrated generally at 50.

The sheet separator 50 serves to separate the original sheet 20 from the copy sheet 22 so that the original sheet will follow a first path of travel 52 passing below the apex 54 of a diverter 56 and through an exit chute 58 so that the original sheet 20 will emerge from the front 19 of the housing 18 and will be passed to a holder 60 mounted upon the housing 18 of the machine 10. The copy sheet 22 will follow a second path of travel 62 which diverges upwardly from the first path of travel 52 so that the copy sheet 22 will engage the diverter 56 above the apex 54 thereof and will be led into the developer section 64 of machine 10. In the developer section 64, the leading edge 32 of the copy sheet 22 will be gripped between a developer drive roller 66, which is rotated in a clockwise direction as shown in FIG. 1, and a fixed web 68 which is perforated so that as the copy sheet 22 passes between the developer drive roller 66 and the fixed web 68 the latent image upon the copy sheet will be exposed to the developer medium within the developer chamber 70, in this instance the medium being gaseous ammonia, to develop the latent image into a visible image on the copy sheet. As the copy sheet 22 emerges from between the developer drive roller 66 and the fixed web 68, the leading edge 32 of the copy sheet 22 will engage a pick-off strip 72 so as to be diverted from the developer drive roller 66 to an exit platform 74. Continued movement of the copy sheet 22 along the exit platform 74 will enable the copy sheet to exit from the rear of housing 18 to be collected by the operator.

Turning now to FIGS. 2 and 3, as well as to FIG. 1, the sheet separator 50 operates to separate the copy sheet 22 from the original sheet by exposing the advancing juxtaposed sheets to opposite areas 80 and 82 of reduced air pressure which are spaced from one another and which, by suction forces, tend to draw the sheets 20 and 22 away from one another. Thus, the sheet separator 50 includes a lower chamber 84 having an uppermost wall 86 which is horizontal and extends laterally across the entire width of the juxtaposed sheets below the first path of travel 52 and has a longitudinal length L which is relatively short compared to the total length of travel of each of the machine 10. The wall 86 of the lower chamber 84 is provided with a plurality of apertures 88 and the interior 89 of the chamber 84 communicates with a blower 90 (shown schematically in FIG. 1) which draws air from the interior of the chamber, thereby establishing the area 80 of reduced air pressure along the outer surface 92 of the upper wall 86 of the chamber 84. Suction forces are thus established which tend to draw and maintain the juxtaposed sheets 20 and 22 against the outer surface 92 of the upper wall 86.

Immediately above the lower chamber 84 is an upper chamber 94 having a lowermost wall 96 which is located above the second path of travel 62 and is likewise provided with a plurality of apertures 98. The interior 99 of the upper chamber 94 is also connected to the blower 90 so that air will be drawn from the upper chamber 94 in order to establish the area 82 of reduced air pressure along the outer surface 102 of the lowermost wall 96 of the upper chamber 94. The lowermost wall 96 also extends laterally in a horizontal direction across the entire width of the juxtaposed sheets 20 and 22 and extends longitudinally over a relatively short length LL which is even shorter than the corresponding length L of the uppermost wall 86 of the lower chamber 84. Thus, the second area 82 of reduced air pressure is provided by the upper chamber 94 and overlaps the first area 80 of reduced pressure provided by the lower chamber 84.

By virtue of the orientation and the relative dimensions of the upper wall 86 of the lower chamber 84 and the lower wall 96 of the upper chamber 94, the first area 80 of reduced air pressure provided by the uppermost wall 86 of the lower chamber 84 extends beyond the second area 82 of reduced air pressure, provided by the lower wall 96 of the upper chamber 94, in the direction of the oncoming juxtaposed sheets 20 and 22 so that the oncoming sheets are first drawn toward the upper wall 86 of the lower chamber 84, along a forward portion 104 of the upper wall 86 which extends along the entrance chute 49 of separator 50 beyond lower wall 96. As the juxtaposed sheets pass between the diverging walls 86 and 96 of the chambers 84 and 94, both the original sheet 20 and the copy sheet 22 will tend to continue to travel along the upper wall 86 of the lower chamber 84 since the tendency of the sheets to cling together may not necessarily be overcome by the divergent opposite areas 80 and 82 of reduced air pressure. In order to overcome the tendency of the sheets to cling together and to achieve a relatively quick separation of the copy sheet 22 from the original sheet 20, a plurality of guides 110 extend upwardly from the upper wall 86 of the lower chamber 84 and intercept the first path of travel 52 along a portion of the longitudinal extent of the first area 80. The guides 110 are spaced laterally over the lateral extent of the upper wall 86, as seen in FIG. 3, so that the advancing juxtaposed sheets 20 and 22 are raised from the upper wall 86 of the lower chamber 84 toward the lower wall 96 of the upper chamber 94, as seen in FIG. 2, at laterally spaced locations. In this manner the copy sheet 22 is picked up by the suction provided at the outer surface 102 of the lower wall 96 of the upper chamber 94 so as to follow the second path of travel 62 while the original sheet 20 conforms to the curvature of the guides 110 and follows the first path of travel 52. The guides 110 are preferably constructed of wire and are curved, or arched upwardly, so that each guide wire is easily located and secured in the upper wall 86 of the lower chamber 84 as shown.

It has been found that in the absence of guides 110 the juxtaposed sheets 20 and 22 would tend to cling to one another and follow either the upper or second path of travel or the lower or first path of travel; however, by first drawing both sheets toward the first path of travel 52 along portion 104 of upper wall 86 and then employing the guides 110 to raise the sheets toward the second path of travel 62, relatively quick and effective separation has been attained. Such separation has been attained over a relatively short longitudinal travel of the sheets and with a minimal reduction of air pressure within the chambers 84 and 94. While ordinarily it would be expected that a considerable reduction in air pressure would be necessary in the upper chamber 94 to raise the copy sheet 22 from the lower path of travel 52, the presence of the guides 110 enables separation with a minimal reduction of the air pressure within the upper chamber, while requiring a minimal reduction of air pressure within the lower chamber to assure that the original sheet 20 follows the first path of travel 52. Thus, the illustrated sheet separator 50 may be operated with the air pressure within the chambers being reduced below ambient air pressure by an amount of only 4 to 6 inches of water column, rendering the sheet separator efficient in that only small amounts of power are necessary to attain the desired results.

Returning now to FIG. 1, where it may be desired to separate the juxtaposed original and copy sheets 20 and 22 manually without passing the copy sheet 22 automatically to the developer section 64, both the original sheet and the juxtaposed copy sheet may be made to exit through the exit chute 58 by manually depressing the diverter 56, which is mounted for pivotal movement at 112 between a first position, shown in full lines in FIG. 1, and a second position, shown in phantom in FIG. 1. By manually depressing the diverter 56 to locate the diverter in the second position, the apex 54 thereof is raised to close the path to the developer section 64. At the same time, a switch 114 is activated to shut off the blower so that the sheet separator 50 is rendered inoperative. The juxtaposed original and copy sheets 20 and 22 will then merely follow the lower path of travel 52 and exit together through the exit chute 58.

It is to be understood that the above detailed description of an embodiment of the invention is provided by way of example only. Various details of design and construction may be modified without departing from the true spirit and scope of the invention as set forth in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a copying machine wherein an original sheet is initially juxtaposed with a copy sheet, the juxtaposed sheets are advanced longitudinally in the machine along a first path of travel, and the original and copy sheets are subsequently separated from one another such that one of said sheets follows a second path of travel which diverges from said first path of travel, a sheet separator comprising:

first means for establishing a first area of reduced air pressure along said first path of travel, said first area extending longitudinally for a relatively short distance along the first path of travel and extending laterally over approximately the width of the advancing sheets;

second means for establishing a second area of reduced air pressure along the second path of travel, said second area essentially overlapping at least a portion of the first area and diverging therefrom in the direction of advancement of said sheets; and

a plurality of guides intercepting the first path of travel along a portion of the longitudinal extent of the first area and spaced laterally over the lateral extent of said first area, said guides being raised from said first area toward the second area to raise the advancing juxtaposed sheets from said first area toward said second area at laterally spaced locations to effect separation of said juxtaposed sheets such that one sheet follows one of said diverging paths of travel while the other sheet follows the other of said paths of travel as the sheets pass between said areas. 2. The invention of claim 1 wherein said first area of reduced air pressure extends beyond the second area of reduced air pressure in the direction of the oncoming juxtaposed sheets.

3. The invention of claim 1 wherein said first means includes:

a first chamber having a wall including an outer surface juxtaposed with said first path of travel; means for drawing air from said first chamber to reduce the air pressure therein; and a plurality of apertures in said wall for establishing said first area of reduced air pressure at the outer surface of the wall. 4. The invention of claim 3 wherein said second means includes:

a second chamber having a wall including an outer surface juxtaposed with said second path of travel; means for drawing air from said second chamber to reduce the air pressure therein; and a plurality of apertures in said wall of the second chamber for establishing said second area of reduced air pressure at the outer surface of the wall of the second chamber.

5. The invention of claim 4 wherein said wall of the first chamber extends beyond said wall of the second chamber in the direction of the oncoming juxtaposed sheets.

6. The invention of claim 4 wherein said guides extend from the wall of the first chamber toward the overlapping wall of the section chamber.

7. The invention of claim 6 wherein each guide is a wire affixed to the wall of the first chamber.

8. The invention of claim 4 wherein:

the first chamber extends horizontally over the width of the advancing sheets below the first path of travel with the outer surface of the wall of the first chamber facing up wardly;

the second chamber extends horizontally over the width of the advancing sheets above the second path of travel with the outer surface of the wall of the second chamber facing downwardly; and

said guides are raised upwardly from the wall of the first chamber toward the wall of the second chamber.

9. The invention of claim 8 wherein each guide is a wire affixed to and arched upwardly from the wall of the first chamber.

10. The invention of claim 9 wherein said wall of the first chamber extends beyond said wall of the second chamber in the direction of the oncoming juxtaposed sheets. 

1. In a copying machine wherein an original sheet is initially juxtaposed with a copy sheet, the juxtaposed sheets are advanced longitudinally in the machine along a first path of travel, and the original and copy sheets are subsequently separated from one another such that one of said sheets follows a second path of travel which diverges from said first path of travel, a sheet separator comprising: first means for establishing a first area of reduced air pressure along said first path of travel, said first area extending longitudinally for a relatively short distance along the first path of travel and extending laterally over approximately the width of the advancing sheets; second means for establishing a second area of reduced air pressure along the second path of travel, said second area essentially overlapping at least a portion of the first area and diverging therefrom in the direction of advancement of said sheets; and a plurality of guides intercepting the first path of travel along a portion of the longitudinal extent of the first area and spaced laterally over the lateral extent of said first area, said guides being raised from said first area toward the second area to raise the advancing juxtaposed sheets from said first area toward said second area at laterally spaced locations to effect separation of said juxtaposed sheets such that one sheet follows one of said diverging paths of travel while the other sheet follows the other of said paths of travel as the sheets pass between said areas.
 2. The invention of claim 1 wherein said first area of reduced air pressure extends beyond the second area of reduced air pressure in the direction of the oncoming juxtaposed sheets.
 3. The invention of claim 1 wherein said first means includes: a first chamber having a wall including an outer surface juxtaposed with said first path of travel; means for drawing air from said first chamber to reduce the air pressure therein; and a plurality of apertures in said wall for establishing said first area of reduced air pressure at the outer surface of the wall.
 4. The invention of claim 3 wherein said second means includes: a second chamber having a wall including an outer surface juxtaposed with said second path of travel; means for drawing air from said second chamber to reduce the air pressure therein; and a plurality of apertures in said wall of the second chamber for establishing said second area of reduced air pressure at the outer surface of the wall of the second chamber.
 5. The invention of claim 4 wherein said wall of the first chamber extends beyond said wall of the second chamber in the direction of the oncoming juxtaposed sheets.
 6. The invention of claim 4 wherein said guides extend from the wall of the first chamber toward the overlapping wall of the section chamber.
 7. The invention of claim 6 wherein each guide is a wire affixed to the wall of the first chamber.
 8. The invention of claim 4 wherein: the first chamber extends horizontally over the width of the advancing sheets below the first path of travel with the outer surface of the wall of the first chamber facing upwardly; the second chamber extends horizontally over the widTh of the advancing sheets above the second path of travel with the outer surface of the wall of the second chamber facing downwardly; and said guides are raised upwardly from the wall of the first chamber toward the wall of the second chamber.
 9. The invention of claim 8 wherein each guide is a wire affixed to and arched upwardly from the wall of the first chamber.
 10. The invention of claim 9 wherein said wall of the first chamber extends beyond said wall of the second chamber in the direction of the oncoming juxtaposed sheets. 